http://sheilaaliens.net/?p=215 "For reasons not fully understood by forecasters, a disturbance rippled through Earth's magnetic field on Feb. 14th. Perhaps it was Cupid's arrow. The impact sparked some sweet lights around the Arctic Circle.
There has been some speculation that the display was caused by a CME, launched from the sun on Feb. 10th and reaching Earth on Feb. 14th. However, there is no clear signature of a CME impact in local solar wind data.
Update: Geomagnetic activity intensified even more on Feb. 15th when the interplanetary magnetic field (IMF) near Earth tilted south, opening a crack in Earth's magnetic field. Solar wind poured in and fueled a G1-class geomagnetic storm, now subsiding."